Artigo de peri??dico
Photoluminescence of single-phased white light emission materials based on simultaneous Tb3+, Eu3+ and Dy3+ doping in CaWO4 matrix
Registro en:
0925-8388
696
10.1016/j.jallcom.2016.11.378
80.254
Autor
BARBOSA, HELLIOMAR P.
SILVA, IVAN G.N.
FELINTO, MARIA C.F.C.
TEOTONIO, ERCULES E.S.
MALTA, OSCAR L.
BRITO, HERMI F.
Resumen
The triply-doped xTb3??/xEu3??/xDy3?? CaWO4 (x: 0.5, 1.0, 2.0, 3.0, 4.0 and 5.0 mol%) nanomaterials were
prepared at room temperature by a coprecipitation method. The luminescence materials were characterized
by X-ray powder diffraction (XPD), thermal analysis (TG), infrared absorption spectroscopy (FTIR)
and UV excited photoluminescence. The prepared powder phosphors are single-phase scheelite structure
with porous morphology and particle sizes around 11 nm. The materials display white color from cool to
the warm white, under UV excitation, as a result of the intraconfigurational 4f transitions from trivalent
rare earth ions. The non-radiative energy transfer processes from the O/Wand O/Eu LMCT as well as
the 4f8/4f75d1 states to the intraconfigurational 4f excited levels of rare earth ions and simultaneous
emissions from the 4F9/2 (Dy3??)/5D4 (Tb3??)/5D1,5D0 (Eu3??) emitter levels are reported. Furthermore,
CIE parameters and the color correlated temperature (CCT) are discussed in order to characterize the
color emission. Based on the results, these luminescence materials may be potential candidates for white
light emitting diodes and solid-state lighting. Funda????o de Amparo ?? Pesquisa do Estado de S??o Paulo (FAPESP) Coordena????o de Aperfei??oamento de Pessoal de N??vel Superior (CAPES) Conselho Nacional de Desenvolvimento Cient??fico e Tecnol??gico (CNPq) FAPESP: 15/15045-5 CAPES: 04/2008 CNPq: 407820/2013-2